Core B builds on its extensive experience from the prior MIDUS project and will provide the resources and requisite expertise needed to collect and analyze all of the hematological, neuroendocrine, inflammatory and anti-oxidant indices, as well as the biochemical markers of bone turnover, for the proposed research. The BioCore already has the laboratory infrastructure and personnel skills to ensure the collection of reliable and comprehensive data through its centralized and high quality testing and record-keeping. The participant number and time line are in keeping with prior efforts and thus are essentially routine tasks for the BioCore. Specifically, Core B oversees the acquisition and processing of specimens from the regional sites, and either conducts the assays locally or oversees performance of the tests at the clinical laboratories. Our facility is also the initial repository for saliva samples used for assessing Cortisol and alpha-amylase levels, and is the primary liaison with the endocrine laboratory. Over 20,000 salivary specimens have already been processed in this manner. Finally, the BioCore has its own biochemical capabilities for analyses of cytokine levels, and the development of new procedues, and serves an archival function for the long-term storage of all urinary and serum/plasma specimens for the entire MIDUS program. In addition to facilitating the diagnostic testing, the Core is also responsible for the initial log entry of biological data into files of test results, and for resolving any queries or concerns about assay or test results. It oversees all aspects of quality assurance, including periodic Quality Control testing of assay reliability and determines the need for retesting of specimens. To facilitate the archival functions, the Core is the offical repository for all paper records on the hematological and neuroendocrine tests. The BioCore generates "norms" for all test results, both from the MIDUS data as well as via reference to other studies and clinical laboratory values, and thereby also serves a consulting role with respect to the validity and interpretation of physiological findings. During the course ofthe prior MIDUS project, for example, it became evident that some of the standard approaches used for analyzing certain clinical test measures were in need of modification and improvement. In sum, the BioCore provides an efficient, economical, and reliable means for centralized and standardized assessment of biological measures from multiple sites. Through Core B all biological measures for this large national survey are determined in the same testing laboratories using the identical assays with routine Quality Control checks.